Spatial consequences of bleaching adaptation in cat retinal ganglion cells.

1. Experiments were conducted to study the effects of localized bleaching on the centre responses of rod‐driven cat retinal ganglion cells. 2. Stimulation as far as 2 degrees from the bleaching site yielded responses which were reduced nearly as much as those generated at the bleaching site. Bleaching in the receptive field middle reduced responsiveness at a site 1 degrees peripheral more than bleaching at that peripheral site itself. 3. The effectiveness of a bleach in reducing centre responsiveness is related to the sensitivity of the region in which the bleach is applied. 4. Response reduction after a 0.2 degree bleach followed the same temporal pattern for concentric test spots of from 0.2 to 1.8 degrees in diameter, implying a substantially uniform spread of adaptation within these bounds. 5. A linear trade‐off between fraction of rhodopsin and area bleached over a range of 8:1 yields the same pattern of response reduction, implying that the non‐linear nature of bleaching adaptation is a property of the adaptation pool rather than independent photoreceptors.